A 2 year old version of a treasure chest goes down well.
Find a box or bag and fill it with a range of smaller containers that all have something interesting in. You can put container in container in container if they're a child that likes opening things. Use different containers with different fastenings (lid, zip, button, velcro etc).
You can hide small toys (favourites or a small new toy or one they haven't seen for a while), bubbles, a book, a snack, household objects that might be novel to look at (torch, calculator, something that smells nice like bar of soap or drawer freshener thing, notepad and pen, old phone, coins, keys/keyrings, bubble wrap/tin foil/crepe paper). Anything that you think will hold their interest for a few minutes.
You split toys into different hiding places as well so you could e.g. teddy's hat and then you have to look through and find teddy! Or hide puzzle pieces. Of cut a picture in half and they can assemble it when they find both pieces.